Die accelerator mechanism



May 31, 1966 E. R. BODNAR DIE ACCELERATOR MECHANISM 5 Sheets-Sheet 1 Filed Feb. 19, 1965 INVENTOR.

ERNEST ROBERT BODNAR I N VEN TOR. ERNEST ROBERT BODNAR NOE 5 Sheets-Sheet 2 Filed Feb. 19, 1965 Cd uanagA 8 Warman May 31, 1966 E. R. BODNAR DIE ACCELERATOR MECHANISM 5 Sheets-Sheet 5 Filed Feb. 19, 1965 INVENTOR.

ERN EST ROBERT BODNAR al/army &" War/nan United States Patent 3,253,490 DIE ACCELERATOR MECHANISM Ernest Robert Bodnar, 29 Blacltdown Crescent, Islington, Ontario, Canada Filed Feb. 19, 1965, Ser. No. 433,924 7 Claims. (Cl. 83-287) The invention relates to cut-01f die apparatus for use in a sheet metal working line.

In a sheet metal working line it is desirable to maintain said sheet metal in continuous motion in order that the same may be continuously Worked or shaped without a pause. At the end of such a line the sheet metal is generally severed into lengths for shipping or storage, and in order to achieve such cutting, a movable cut-off die is provided, which is reciprocable along the path of movement of said sheet metal and operable during such movement to sever the same without necessitating a pause in the movement thereof. Such prior cut-off die apparatus as has generally been available has suffered from a variety of difficulties. For example, the speed of movement of prior cut-off dies has sometimes been erratic or variable with the result that at the time of shearing of the sheet metal it was moving either faster or slower and thus damaging a portion thereof. Further, such prior apparatus has rendered it difficult to out said sheet metal to precise lengths, resulting in wastage thereof, and sometimes involving a further trimming operation.

A greatly improved form of cut-off die is disclosed in my prior Canadian Let-tens Patent No. 667,957, issued Aug. 6, 1963, for Die Accelerator & Control Mechanism wherein greater accuracy of acceleration and cutting is achieved. My prior cut-off die incorporated a rack and pinion for driving of the die carriage on its forward stroke and air cylinder on its return stroke and it has been found that, particularly when operating at the upper limit of its speed of operation, or when applied to a very large installation, the large inertial forces tend to cause the-die carriage to twist to and fro, with greatly increased power consumption and wear and further that such forces are difficult to control and reverse within the limits of the available path in the apparatus.

It is therefore an objective of the invention to provide cut-off die apparatus of the type described which is adapted to cut sheet metal while in motion in an economical and expeditious manner and With a minimum wastage of time and materials.

More specifically, it is an object of the invention to provide cut-off die apparatus having the foregoing advantages which is adapted to cut said sheet metal into precise lengths and without damaging the same or causing a pause or break in the movement thereof.

More specifically it is an objective of the invention to provide a cut-off die apparatus having the foregoing advantages in which cut-off die carriage is buffered to reduce its speed at each end of its stroke.

More specifically it is an objective of the invention to provide a cut-off die apparatus in which the cut-off die carriage is driven on the forward stroke by drive means spaced apart on each side of its path of movement.

More specifically it is an objective of the invention to provide a cut-off die apparatus in which the control system is operable to procure buffering of the movement of the cut-off die carriage.

It is a further objective to provide cut-off die apparatus having the foregoing advantages in which the speed of reciprocation may be varied during the operation thereof.

It is a further objective of .the invention to provide cut-off die apparatus having the foregoing advantages which is fully automatic in operation and requires only a minimum of supervision.

The foregoing and other advantages will become apparent from the following description of a preferred embodiment of the invention which will be described with reference to the following drawings in which like reference devices refer to like parts thereof throughout the various views and diagrams, and in which:

FIGURE 1 is an isometric view of cut-off die apparatus according to the invention, showing portions thereof in phantom and from which the various control devices have been omitted for the sake of clarity;

FIGURE 2 is an elevation view partly in section of the apparatus shown in FIGURE 1 and also showing a portion of the sheet metal working line in association with which it is used and in addition, showing the various control devices superimposed thereon in phantom;

FIGURE 3 is a top plan view of the apparatus of FIGURE 1;

FIGURE 4 is an enlarged section along the line 44 of FIGURE 3, and

FIGURE 5 is a block circuit diagram of the electrical controls.

Referring to the drawings it will be seen that this preferred embodiment of the invention comprises upper and lower cut-off die halves It) and 11 which are shaped according to the configuration of the sheet metal 12 leaving the working line (the details of which have been omitted for the sake of clarity). Die halves 1t] and 11 are mounted on a die carriage assembly comprising a respective upper and lower platens 13 and 14 which are reciprocable towards and away from one another on mounting posts 15 which are adapted to telescope one within the other to permit such reciprocation. Platens 13 and 14 are in turn fastened to respective upper and lower slides 16 and 17 which run on respective guide rails 18 and 19 to permit reciprocal movement to and fro on a predetermined path-along the line of movement of sheet metal f2. Guide rails 19 are fastened to bed plate 20, and guide rails 18 are fastened to movable plate 21, which is itself mounted on adjustable pillars 22 which are slidably mounted in bed plate 20.

Any suitable die operating mechanism may be provided below bed plate 20 for procuring rapid reciprocation of movable plate 21 towards and away therefrom,

and driven by a constant speed electric motor 23, through drive mechanism 24 and air clutch 25, air valve 26 being provided to procure intermittent operation thereof. Bed plate 29 is supported at an elevation by side walls 27 and fastened in position by base 28.

Brake mechanism 29 is provided, of any suitable de-' sign which, in this preferred embodiment is operated and controlled by air valve 30, such brake mechanism operating along the same axis as clutch 25 and acting on a crank shaft (not shown) extending therebetween and forming part of the die operating mechanism, the details of which have been omitted for clarity.

Mechanical means are provided to procure forward acceleration of platens 13 and 14, and cut-off die halves 10 and 11 fastened thereto, and comprising a pair of driving rods 31 are attached to platen 14 by bolts 32 along each side thereof, and extending rearwardly therefrom. On their underside is provided racking 33 for driving in the forward direction by pinions 34 meshing with racking 33, which are in turn driven through air operated clutch 35, and variable speed drive 36 by a constant speed electric motor (not shown). Manual control means (not shown) may be provided on variable drive 36 for regulating the speed thereof to procure forward acceleration of die halves 10 and 11 up to the same speed as that of the sheet metal. Clutch 35 is operated by electrically controlled air valve 37 to procure intermittent acceleration in a manner to be described hereinafter.

age thereto by bending or flexing thereof.

Pneumatic means are provided to return platens 14 and 15 and die halves 10 and 11 fastened thereto rearwardly, after the cutting of the sheet metal comprising cylinder rod. 38 attached to platen 14 and extending therefrom into pneumatic cylinder 39 and fastened to the piston thereof (not shown) therewithin. Electrically controlled air valve 40 is provided for admitting air to cylinder 39 and procuring rearward movement of rod 38, and for permitting escape of air therefrom during forward acceleration, and also to close the same to terminate escape of air and provide a pneumatic buffering action at the end of the forward acceleration stroke.

Shock absorber means comprising hydraulic cylinders 41 are provided mounted on support bar 42 adjacent to the rearward, at rest, position of platens 13 and 14 and aligned parallel with the path of movement thereof, and having buffer rods 43 extending therefrom into contact with, but unattached to the rearward edge of platen 14 for buffering the rearward stroke thereof. Cylinders 41 are provided with known spring means (not shown) causing extension of rods 43 therefrom when freed by forward acceleration of platen 14.

Adjustable guide means are provided for limiting sideways movement or turning of platen 14 and for taking up wear which comprises the guide rail 44 fastened to bed plate 20 alongside rod 31 by means of bolts 45 passing through oversize holes 46 therein. Bearing edge 47 extends along the inner side of guide rail 44 for contacting rod 31 (see FIGURES 3 and 4). Guide rail 44 is itself located in precise position by means of reference rail 48 fastened to bed plate 26 parallel to guide rail 44 by means of bolts 49 so as to be incapable of adjustment. Spaced bolts 50 extend horizontally through reference rail 48 for moving and locating guide rail 44 and. are locatable by means of lock nuts 51. Shield 52 is provided to cover the foregoing members and to guide sheet metal directly between cut-off die halves 10 and 11.

A suitable run-out table 53 supported in position on legs 54 is provided for supporting sheet metal passing between cut-off die halves 10 and 11 and to prevent dam- Table 53 is preferably provided with an adjustable length indicator 55 having an indicator arm 56 normally oriented in the path of sheet metal advancing along run-out table 53. Indicator member 55 is adjustably located on the sliding rod member 57 one end of which is fastened to the lower cut-off die half 11, and the other end of which is slidably supported within the sleeve member 58. Sleeve member 58 is rotatably mounted on table 53 and is provided with means for rotating the same through approximately 90 degrees of rotation comprising pneumatic cylinder 59 and lever arm 60 attached to sleeve 58 whereby rod 57 and indicator member 55 attached thereto may be rotated through approximately 90 degrees to bring arm member 56 out of the path of sheet metal on table 53 allowing the same to pass thereby after completion of the cutting stroke.

Measuring of lengths of sheet metal passing between cut-off die halves 10 and 11 may be achieved by means of a rotating measuring unit such as is indicated generally by reference 61 operable to deliver a predetermined number of electrical signals in response to passage of sheet metal in engagement therewith which signals may be utilized to operate any suitable digital counter such as is generally indicated by reference 62, substantially in the manner described in my aforesaid Canadian Letters Patent No. 667,957. Counter 62 operates, as described in the aforesaid Letters Patent No. 667,957 to deliver a triggering impulse to electrical solenoid 63 associated with the pneumatic valve 37 thereby operating air clutch 35 and causing rotation of pinions 34 thereby driving cut-oflf die halves 10 and 11 forwardly. However, according to a further preferred form of the invention measuring device 61 and counter 62 are dispensed with and in place, a triggered impulse is supplied by means of limit switch 64 which is movably locatable along table 53 and is provided with contact arm 65 located in the path of sheet metal moving along table 53 for operation of switch 64. Electrical solenoid 66 associated with pneumatic valve 40 is connected to switch 67 operated by cam 68 mounted on the crank shaft (not shown) of the cut-off die operating mechanism, electrical solenoid 69 is associated with pneumatic valve 26 for operation thereof and is connected to limit switch 70 located in the path of movement of lower platen 14, and electrical solenoid 71 is associated with pneumatic valve 30 for operation thereof and is connected to switch 72 operated by cam 73 mounted concentrically with cam 68 aforesaid. In addition, as a safety measure, an over-run limit switch 74 may be provided in the path of movement of lower platen 14 and beyond the normal limit of travel thereof which is connected to any suitable relay 75 for immediately terminating supply of electrical power to the entire installation.

For providing early closing of pneumatic cylinder 39 to prevent further escape of air therefrom an additional switch 76 is provided for operation by cam 68 and connected to electrical solenoid 66 for operating pneumatic valve 40 to close the same. A further pneumatic valve 77 is provided for operation of air cylinder 59 and having electrical solenoid 78 associated therewith connected to and controlled by limit switch 79 located in the path of movement of platen 14.

In operation, cut-off die halves 10 and 11 will be normally apart from one another and at the rearward end of their stroke. In this position, sheet metal will pass therebetween at a predetermined speed until the leading edge of the sheet metal strikes arm 65 of switch 64. Switch 64 will thereupon deliver a triggering impulse to solenoid 63 which operates pneumatic valve 37 thereby operating clutch 35 and causing rotation of pinions 34 and driving rods 31 forwardly. Forward movement of rods 31 will carry with them upper and lower platens 13 and 14 and upper and lower die halves 10 and 11 and accelerate them up to the speed of the sheet metal passing therebetween at which point lower platen 14 will contact limit switch 70 and deliver an impulse to solenoid 69 thereby operating pneumatic valve 26. Pneumatic valve 26 thereby operates air clutch 25 and applies powerfrom motor 23 to the crank shaft (not shown) thereby causing immediate downward motion of upper plate 21 carrying with it upper platen 13 and upper die half 10 and severing the sheet metal. Simultaneously, with such severing motion, the further end of the sheet metal will have contacted arm 56 of member 55 which is moving along table 53 at the same speed as platens 13 and 14, being fastened thereby by rod 58, thereby giving a visual indication of the precise length of the sheet metal being severed by that particular operation. As the crank shaft (not shown) completes its revolution die half 10 and upper platen 13 and under plate 12 will be raised to their upper position permitting sheet metal to continue to pass between upper and lower die halves 10 and 11 and leaving the severed length of sheet metal lying freely on table 53. As soon as cut-ofi? die halves 10 and 11 begin to move apart from one another as aforesaid, it is necessary to begin deacceleration of their forward movement and for this purpose cam 68 is located so as to trip switch 76 and send an impulse to solenoid 66 which operates pneumatic valve 40 and closes pneumatic cylinder 39 against further escape of air thereby applying a cushioning or buffering effect rapidly slowly down forward movement of cut-off die halves 10 and 11 and platens 13 and 14. As plate 21 reaches its highest position once more cam 68 trips switch 67 and sends a further signal to solenoid 66 operating pneumatic valve 40 and the same signal is also communicated to solenoid 63 operating valve 37 and releasing air clutch 35. Operation of pneumatic valve 40 applies compressed air to the interior of cylinder 39 and procures movement of platens 13 and 14 and die halves 10 and 11 in the rearward direction on their return stroke. Just before such return stroke commences, pneumatic cylinder 59 is operated by limit switch 79, solenoid 78 and valve 77, to rotate sleeve 58 and rod 57 through approximately 90 degrees to bring arm 56 of member 55 substantially vertical thereby freeing the same from the end of the piece of sheet metal lying on table 53 and permitting the same to move rearwardly once more in unison with platens 13 and 14. Roughly simultaneously with the termination of the forward stroke of platens 13 and 14, upper plate 21 and upper platen 13 and upper die half will have reached their uppermost position once more and cam 73 is so located as to trip switch 72 at this point thereby operating solenoid 71 which in turn operates pneumatic valve 30 and causes brake 29 to check further rotation of the crank shaft (not shown). As the upper and lower platens 13 and 14 move rearwardly they will accelerate to a maximum speed after which they must be deaccelerated and halted in their rearward position ready for the next stroke. Such deacceleration and buffering is achieved by means of hydraulic cylinders 41 and rods 43 extending forwardly therefrom which are located in the path of rearward movement of lower platen 14 and function substantially as shock absorbers therefor, thereby avoiding the development of unnecessary shocks in the apparatus.

From the foregoing, it will be seen that precise control of the length of sheet metal being sheared can be maintained by means of moving limit switch 64 on table 53 either closer to or further away from cut-off die halves 10 and 11 and at the same time a close visual check can be kept on the accuracy of shearing during operation by means of the operator watching the movement of arm 56' and member 55. Even in the case of very large installation, the tendency for upper and lower platens 13 and 14 to twist as they move forwardly is avoided by the use of twin rods 31 and pinions 34 driving the same from each side thereof and by the accurate control of wear developing in the apparatus by means of the adjustment provided in rail 44. Excessive wear due to continual shocks developed in the apparatus in operation is avoided by means of the buffering of forward movement by early closure of the pneumatic cylinder and buffering in the reverse direction is achieved by means of hydraulic cylinders thereby smoothing out the deacceleration to a substantial degree,

The foregoing is a description of a preferred embodiment of the invention which is here made by way of example only. The invention is not to be taken as limited to the specific steps described but comprehends all such variations that come within the spirit and scope of the appended claims.

What I claim is:

1. Cut-off die apparatus for use in association with a sheet metalworking line for shearing sheet metal to predetermined lengths while moving along said line, said apparatus comprising:

a die press including a press operating mechanism;

a cut-off die carriage means reciprocably mounted in said press for forward and return movement;

at least two rack members connected to said carriage means in spaced apart parallel relation;

pinion members engaging respective said rack members and having a power source connectable thereto;

a length sensor located in the path of said sheet metal delivering a triggering signal to said power source; pneumatic cylinder means connected to said carriage means and having valve control means therefor; switch means responsive to acceleration of said die carriage means to trigger said die press operating mechanism;

and switch means responsive to operation of said die press to trigger said pneumatic cylinder.

2. Cut-off die apparatus for use in association with a sheet metal working line for shearing sheet metal to predetermined lengths while moving along said line, said carriage means to trigger said die press operating mechanism; pneumatic cylinder means connected to said carriage means and having valve control means therefor; switch means responsive to operation of said die press to trigger said pneumatic cylinder;

and switch means responsive to partial operation of said die press to close said pneumatic cylinder.

3. Cut-off die apparatus for use in association with a sheet metal working line for shearing sheet metal to predetermined lengths while moving along said line, said apparatus comprising:

a die press including a press operating mechanism;

a cut-off die carriage means reciprocably mounted in said press for forward and return movement;

at least two rack members connected to said carriage means in spaced apart parallel relation;

pinion members engaging respective said rack members and having a power source connectable thereto; a length sensor located in the path of said sheet metal delivering a triggering signal to said power source;

switch means responsive to acceleration of said die carriage means to trigger said die press operating mechanism;

pneumatic cylinder means connected to said carriage means andhaving valve control means therefor; switch means responsive to operation of said die press to trigger said pneumatic cylinder;

and buffer means operable on said carriage means to deaccelerate movement thereof.

4. Cut-off die apparatus for use in association with a sheet metal working line for shearing sheet metal to predetermined lengths while moving along said line, said apparatus comprising:

a die press including a press operatingmechanism;

a cut-ofi. die carriage means reciprocably mounted in said press for forward and return movement;

rack and pinion means coupled to a power source and connected to said die carriage means; a length sensor located in the path of said sheet metal delivering a triggering signal to said power source;

switch means responsive to acceleration of said die carriage means to trigger said die press operating mechanism;

pneumatic cylinder means connected to said carriage means and having valve control means therefor; switch means responsive to operation of said die press to trigger said pneumatic cylinder;

visual length indicator means coupled to said die carriage means in the path of said sheet metal and movable in unison therewith;

and indicator release means connected to said indicator means for moving same out of the path of said sheet metal. 65 5. Cut-off die apparatus for use in association with a sheet metal working line for shearing sheet metal to predetermined lengths While moving along said line, said apparatus comprising:

a die press including a press operating mechanism;

a cut-01f die carriage means reciprocably mounted in said press for forward and return movement;

at least two rack members connected to said carriage means in spaced apart parallel relation;

pinion members engaging respective said rack members and having a power source connectable thereto;

determined lengths while apparatus comprising:

moving along said line, said a die press including a press operating mechanism; a cut-off die carriage means reciprocably mounted in mechanism; said press for forward and return movement;

pneumatic cylinder means connected to said carriage at least two rack members connected to said carriage means and having valve control means therefor; means in spaced apart parallel relation;

switch means responsive to operation of said die press pinion members engaging respective said rack members to trigger said pneumatic cylinder; and having a power source connectable thereto;

and hydraulic buffer members mounted adjacent said 10 a length sensor located in the path of said sheet metal die carriage means in the return path thereof. 6. Cut-off die apparatus for use in association with a delivering a triggering signal to said power source; switch means responsive to acceleration of said die carriage means to trigger said die press operating mechanism; pneumatic cylinder means connected to said carriage sheet metal working line for shearing sheet metal to predetermined lengths while moving along said line, said apparatus comprising:

means and having valve control means therefor; switch means responsive to operation of said die press to trigger said pneumatic cylinder; switch means responsive to partial operation of said die press to close said pneumatic cylinder; hydraulic buffer members mountde adjacent said die carriage means in the return path thereof; guide rail means mounted adjacent at least one said rack member and having means for adjustably reswitch means responsive to acceleration of said die locating same to maintain substantially constant carriage means to trigger said die press operating Spacing thel'ebetweell; mechanism; visual length indicator means coupled to said die carpneumatic cylinder means connected to said carriage fiage means in the P of saidsheet metal and m means and having valve control means'therefor; able in unison thefBWith;

switch means responsive to operation of said die press and indicator release means connected to said indicator to trigger said pneumatic cylinder;

and guide rail means mounted adjacent at least one said rack member and having means for adjustably Te-locating same to maintain substantially constant spacing therebetween.

7. Cut-off die apparatus for use in association with a sheet metal Working line for shearing sheet metal to premeans for moving same out of the path of said sheet metal.

No references cited.

WILLIAM W. DYER, ]R., Primary Examiner. L. TAYLOR, Assistant Examiner. 

1. CUT-OFF DIE APPARATUS FOR USE IN ASSOCIATION WITH A SHEET METAL WORKING LINE FOR SHEARING SHEET METAL TO PREDETERMINED LENGTHS WHILE MOVING ALONG SAID LINE, SAID APPARATUS COMPRISING: A DIE PRESS INCLUDING A PRESS OPERATING MECHANISM; A CUT-OFF DIE CARRIAGE MEANS RECIPROCABLY MOUNTED IN SAID PRESS FOR FORWARD AND RETURN MOVEMENT; AT LEAST TWO RACK MEMBERS CONNECTED TO SAID CARRIAGE MEANS IN SPACED APART PARALLEL RELATION; PINION MEMBERS ENGAGING RESPECTIVE SAID RACK MEMBERS AND HAVING A POWER SOURCE CONNECTABLE THERETO; A LENGTH SENSOR LOCATED IN THE PATH OF SAID SHEET METAL DELIVERING A TRIGGERING SIGNAL TO SAID POWER SOURCE; PNEUMATIC CYLINDER MEANS CONNECTED TO SAID CARRIAGE MEANS AND HAVING VALVE CONTROL MEANS THEREFOR; SWITCH MEANS RESPONSIVE TO ACCELERATION OF SAID DIE CARRIAGE MEANS TO TRIGGER SAID DIE PRESS OPERATING MECHANISM; AND SWITCH MEANS RESPONSIVE TO OPERATION OF SAID DIE PRESS TO TRIGGER SAID PNEUMATIC CYLINDER. 